one of those is exactly what i need for dogs!!!!
They mainly seem to be on the Mk1s, seen a handfull on early Mk2s.
Was the largest opening roof of its kind or something like that at the time introduced.
Mine had a tear in it gaffa taped up when i bought the van and had been bodged to stay shut. Went to the dealers to price up a new fabric and motor to repair. The motor was something like £278 +VAT from memory, the fabric was not available seperately, you have to buy a whole lot at a massive £4000 +VAT ! ! ! The parts guy said he'd never sold one, i can't think why!
The whole thing can be removed from the roof and taken apart/overhauled.
I looked into getting mine recovered by an upolsterer in mohair or something like that, could choose what colour i wanted... wasn't too pricey. To repair mine i found a good complete second hand one in the end for less than the price of just a new motor.
It was made by Tudor Webasto.